In wide area wireless communication networks, relatively high power base station devices are provided to serve wireless client devices. Each base station device is capable of serving wireless client devices in a coverage area that is primarily determined by the power of the signal it can transmit. Wireless service to client devices located within large buildings becomes degraded because the client device has difficulty receiving a signal from the base station, even if the building is well within the coverage area of the base station.
To augment the coverage of the wireless network, wireless transceiver devices with relatively small coverage areas (and serving capacities) are deployed. Depending on their coverage area and serving capacities, these wireless transceiver devices are referred to as “femto” cell or “pico” cell access point devices. For simplicity and generality, the term radio access point (RAP) device is meant to refer to a wireless transceiver device that is configured to serve wireless client devices over relatively small coverage areas and with generally less capacity as compared to a macro base station that is configured to serve a relatively large coverage area (“macro cell”) and consequently many more client devices. The RAP devices may be deployed inside or near buildings to serve client devices where signals from a macro base station are too weak. The process of handover from a macro base station to a RAP device is referred to here as hand-in.
To facilitate the hand-in, the client device is instructed to perform radio measurements on various channels and report back signal strength for each frequency channel and primary scrambling code (PSC) on which a broadcast signal from a macro base station or RAP device was detected. A radio network controller associated with the macro base station receives the measurement reports and makes decisions to handover the client device to a RAP device based on signal quality. The radio network controller is configured to associate each frequency channel/PSC in the measurement report that comprises a target cell identifier.
According to current 3GPP wireless communication standards, the neighbor cell list broadcasted by a macro base station (and by the RAP device) to client devices contains a list of frequency channel and PSC combinations. The number of entries in this list is limited, e.g., 32 intra-frequency entries and 32 inter-frequency entries. In RAP device deployments there are situations when there are insufficient neighbor cell entries to uniquely identify each enterprise RAP cell within a macro cell coverage area.